A while back I was towing my boat down to the coast with my '92 Bronco. On the way down, the MIL (check engine) light came on, the torque converter went to non-lockup and the engine high-idled at about 1200. I assumed it went into LOS (limp) mode for some reason. More on that later.
The Big Problem- when I went to launch my boat I noticed ATF all over the bow of the boat and the tailgate of my Bronco. A quick check underneath and I saw more ATF all over the trans, transfer case and driveline. It had blown fluid all over the place at highway speed so I couldn't pinpoint the leak. I put 2 quarts of ATF in it and limped 'er home.
Weird thing is, it didn't leak anymore. I was sure I blew a pump seal since the mess appeared to be starting at the bellhousing area. Isn't there a vent somewhere on top of the trans? Would running 60 miles or so with no lockup cause the trans to heat up and blow fluid? I read somewhere that limp mode will bump the trans pressure up to the max. I didn't think the converter not locking up would be a big deal. I parked it and didn't get the chance to pull codes before I put it in storage a few weeks later. I'm gonna go get it pretty soon so I'm making a list of things I have to fix when I get it back up here, and this is at the top of the list. Any opinions would be appreciated!

 

There is a vent on the top of the case pretty much in the middle, maybe a little towards the front. There is no problem running without the converter locked, unless you were running without the switch applied like it seems and it was still unlocked. In that case I dont know if that would hurt anything, but it's not normal. Just by using logic it seems if there is oil on the front of the bellhousing it might be a pump seal. If it was coming from the vent it might just blow back and not forwards, but that's just guessing. You never know what could really happen to that fluid under there. Running without the converter locked would not normally heat up the fluid too hot, but limp mode may affect things differently.

There was same other post on here of some guy towing and his blew oil out the pump seal, but it never did it again afterwards. I don't know if he ever figured it out or not. You might try and see if you can find that thread, it was posted within the last month and a half or so.

 

Thanx for the tip. I'll look for that thread. BTW, I didn't have the OD locked out. My little boat, motor and trailer only weighs about 1000 lbs and you can barely tell it's back there. I usually lock the OD out around town to keep it from going in to OD too early, which annoys me.